Various modifications of a therapeutic "compress" of the type employing a resilient container or envelope in which is hermetically sealed a low freezing point and/or high boiling point liquid are disclosed in U.S. Pat. Nos. 1,964,655; 2,375,087; 2,547,886; 2,697,424; 2,715,315; 2,749,914; 2,783,806; 3,092,112; and 3,349,825.
In particular, U.S. Pat. No. 3,092,112 discloses the use of 1,2-propane-diol (also known as "propylene glycol") sealed within thermoplastic envelope materials of the halogen modified type. 1,2-propane-diol is stated to be particularly advantageous in that it has a low vapor pressure at ambient temperatures, a high boiling point, is liquid at sub-zero temperatures, is non-toxic, resists mold formation and is substantially chemically inert with thermoplastic envelope materials of the halogen modified type for prolonged periods of time. Disclosed envelope materials include elastomers, as well as thermoplastics, such as polyvinyl chloride. It is pointed out that the liquid can be dyed, and that the envelope material may or may not be transparent in color.
The prior art also discloses various structures in which the envelope may be packaged or placed, such as a jacket (U.S. Pat. No. 2,403,676), or shapes that the envelope may take, such as a bag shaped to conform to the forehead of a person (U.S. Pat. No. 1,964,655).
Unlike the present invention, however, these "antiseptic-appearing" prior art structures, offer little to sustain the limited attention of children to continuously holding the compress in place once it is prepared for use, by heating, or cooling, as appropriate. The psychological soothing and calming effect of even conventional stuffed fabric toys upon children is well known. For this reason, the present invention is doubly advantageous for use with children with its added medically therapeutic value.
Also, since in the present invention, an outer fabric layer or member effectively "insulates" from the user the envelope or container, after it has been prepared for use and inserted into an interior pocket of the toy, through an opening in the outer layer or member of the toy, the prior art problem of too direct an application of the envelope, or container, to the skin, which can in certain instances otherwise cause burning due to extreme heat or cold of the liquid, is solved.
Further, in this manner also solved is the prior art problem of too quick of a dissipation of the heat or cold, as the case may be, of the liquid within the envelope or container.
Finally, the prior art problem of preventing access to the liquid during use by children is solved.